DESCRIPTION Amblyopia is considered to be a permanent reduction in vision that arises from abnormal visual experience early in life, affecting 2-3% of the general population. The primary treatment for amblyopia in children, for the last 250 years has consisted of patching the fellow eye. Patching is considered to be ineffective in adults and is seldom, if ever used. Our main aim is to develop new interventions that embed visual training in active and rewarding visuomotor tasks for restoring both visual acuity and stereopsis in adults and children with amblyopia and to compare it to the traditional treatment of patching. The first such intervention is action videogame playing. This activity enhances aspects of vision in young healthy eyes that are known to be deficient in amblyopic eyes. We ask whether action video game playing may be useful in restoring visual functions in amblyopic eyes. Specifically we will develop and test a customized videogame which enables the presentation of designer targets. An important goal is to promote coordination between the two eyes, therefore we will develop a new interface that uses filtering to degrade the image being sent to the fellow eye in order to match the level of the amblyopic eye. Training will therefore require patients to play an action video game with roughly balanced binocular input. While action games appear most effective in enhancing vision in young adults with normal vision, these games are not appropriate for pediatric populations, thus we also propose to develop and test a videogame that is child friendly using the same principles. The second intervention, focused directly on retraining stereopsis, is visually guided hand movements in a virtual-reality environment in which we can manipulate different cues to depth and in which patients receive implicit performance feedback embedded in the task. We ask whether this virtual reality training, which capitalizes on our previous work on how monocular and stereo cues combine to support depth perception, may promote fusion and stereopsis. A strength of this joint proposal between UC Berkeley and U of Rochester is in our outcome measures. We will evaluate and quantify a broad range of visual functions including stereopsis in amblyopic subjects. Our pilot data suggests that improving visual acuity and stereopsis is an achievable goal even in adult patients. A commercially available video game has been adapted to the needs of this project in collaboration with game designers, and will be made freely available to eye clinics for a randomized clinical trial if the project is successful.